Explain what is meant by efficiency?

Efficiency is the degree of perfection in which one quantity is converted into another. For example a farmer will be interested in the efficiency with which cattle convert grass into beef weight.

Note Efficiency and effectiveness are often confused with each other.

Effectiveness concerns itself principally with the outcome. Even if excessive input was used, as long as the desired output was achieved, then effectiveness is gained.

example. Even if it cost a few millions of dollars to cap the BP well, as long as it was successful, it was effective.